'Foley' is said to have been derived from the Old Irish 'foghláda/foghládha - 'raider' or 'plunderer' - a clear pointer to Viking/Norse/Danish inroaders.
And of course, we must not overlook the present US president - Bairác Ó Bamheadhe.
|Mac SEARRAIGH—IV—M'Sharrie, MacSharry, MacSherry, Sharry, Sherry, and, by translation, Feley, Foley; 'son of Searrach' (foal, flighty); an old Breifney surname; found in the 16th century in Leitrim, Cavan and Sligo, where it is still common; now also in Armagh and Donegal. There was also a family of the name in Co. Down which cannot now be traced unless changed to Ó Searraigh (which see), which is not improbable. Searrach signifies a foal, hence the translated forms Feley (Filly) and Foley, the latter common about the town of Sligo.|